What was known on health risks in people living close to mobile phone masts before 5G roll-out?

Klaus Buchner is a German university professor, physicist, and a former MEP (ÖDP). He has represented the European Parliament Germany constituency since 2014. He set with the Greens–European Free Alliance group in the European Parliament. He was Leader of the ÖDP from 2003 to 2010. Buchner was a fellow of the European Institute for International Law and International Relations.